From 34212cc7df317a058a3f9860fc0e7de508cb7120 Mon Sep 17 00:00:00 2001
From: Todd Kennedy <toddke@google.com>
Date: Tue, 25 Jan 2011 08:26:27 -0800
Subject: [PATCH] Infer attachment's mime type if it's text/plain

If the server reports an attachment's mime type as either text/plain or
application/octet-stream, we will try to infer the real mime type using
the attachment's extension. If one cannot be found, we either synthesize
it (if original mime type is application-octet-stream), or, we use the
server specified mime type (if the original is text/plain).

bug 3379416

Change-Id: I331e767ed36e4e17756025cc816bdb7b5a8f0868
---
 src/com/android/email/provider/AttachmentProvider.java     | 7 ++++---
 .../android/email/provider/AttachmentProviderTests.java    | 6 ++++++
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/src/com/android/email/provider/AttachmentProvider.java b/src/com/android/email/provider/AttachmentProvider.java
index f020d1627..71a20f427 100644
--- a/src/com/android/email/provider/AttachmentProvider.java
+++ b/src/com/android/email/provider/AttachmentProvider.java
@@ -201,13 +201,13 @@ public class AttachmentProvider extends ContentProvider {
         // NOTE mime-types are case-*sensitive* on Android.
         // Return values from this method MUST always in lowercase.
         String result = null;
-
         if (fileName != null && fileName.toLowerCase().endsWith(".eml")) {
             result = "message/rfc822";
         } else {
             // If the given mime type appears to be non-empty and non-generic - return it
+            boolean isTextPlain = "text/plain".equalsIgnoreCase(mimeType);
             if (!TextUtils.isEmpty(mimeType) &&
-                    !"application/octet-stream".equalsIgnoreCase(mimeType)) {
+                    !"application/octet-stream".equalsIgnoreCase(mimeType) && !isTextPlain) {
                 result = mimeType;
             } else {
                 // Try to find an extension in the filename
@@ -217,7 +217,8 @@ public class AttachmentProvider extends ContentProvider {
                         // Extension found.  Look up mime type, or synthesize if none found.
                         result = MimeTypeMap.getSingleton().getMimeTypeFromExtension(extension);
                         if (TextUtils.isEmpty(result)) {
-                            result = "application/" + extension;
+                            // If original mimetype is text/plain, us it; otherwise synthesize
+                            result = isTextPlain ? mimeType : "application/" + extension;
                         }
                     }
                 }
diff --git a/tests/src/com/android/email/provider/AttachmentProviderTests.java b/tests/src/com/android/email/provider/AttachmentProviderTests.java
index 7a2cf43db..9a830dbe8 100644
--- a/tests/src/com/android/email/provider/AttachmentProviderTests.java
+++ b/tests/src/com/android/email/provider/AttachmentProviderTests.java
@@ -366,6 +366,7 @@ public class AttachmentProviderTests extends ProviderTestCase2<AttachmentProvide
     public void testInferMimeType() {
         final String DEFAULT_MIX = "Application/Octet-stream";
         final String DEFAULT_LOWER = DEFAULT_MIX.toLowerCase();
+        final String TEXT_PLAIN = "text/plain";
         final String FILE_PDF = "myfile.false.pDf";
         final String FILE_ABC = "myfile.false.aBc";
         final String FILE_NO_EXT = "myfile";
@@ -393,6 +394,11 @@ public class AttachmentProviderTests extends ProviderTestCase2<AttachmentProvide
         assertEquals(DEFAULT_LOWER, AttachmentProvider.inferMimeType(null, null));
         assertEquals(DEFAULT_LOWER, AttachmentProvider.inferMimeType("", ""));
 
+        // If mime type can be inferred, return it; otherwise return text/plain
+        assertEquals("application/pdf", AttachmentProvider.inferMimeType(FILE_PDF, TEXT_PLAIN));
+        assertEquals(DEFAULT_LOWER, AttachmentProvider.inferMimeType(FILE_NO_EXT, TEXT_PLAIN));
+        assertEquals(TEXT_PLAIN, AttachmentProvider.inferMimeType(FILE_ABC, TEXT_PLAIN));
+
         // Test for eml files.
         assertEquals("message/rfc822", AttachmentProvider.inferMimeType("a.eMl", "Text/Plain"));
         assertEquals("message/rfc822", AttachmentProvider.inferMimeType("a.eml", DEFAULT_MIX));